FUNGI AND BACTERIA 227 



these spores grow? Why? Formalin or formaldehyde 

 kills the spores as effectively as the hot water. However? 

 it cannot be used about the house for it is poison to human 

 beings. It can be used, however, to great advantage in 

 killing spores that produce fungous diseases of plants. 



What conditions are best suited to the growth of some 

 jungi ? 



Experiments. Place some dry bread on a piece of 

 pasteboard and cover with a tumbler. Beside this place 

 some moistened bread and watch for results. Moisten 

 two pieces of bread and cover with tumblers. Place one 

 where it is warm; the other where it is cool. What con- 

 clusion do you come to in regard to the effect of heat and 

 moisture on the growth of mold? 



What does the mold feed upon? The mushrooms? 

 The apple rot? All of these obtain food from the sub- 

 stances on which they grow. What part of the plant do 

 you think gets the food ? By discussion it may be brought 

 out that the threadlike mycelium which penetrates the 

 substances obtains the food. All fungi such as mold and 

 mushrooms that live upon dead organic matter are called 

 saprophytes. 



Do all jungi live upon dead organic matter, as bread, 

 stumps, etc. ? 



Find some lilac leaves that are covered with a white 

 flourlike growth. This is very abundant on most lilac 

 bushes in the fall. You may find it also on rose leaves. 

 Examine the leaves closely. You will find the white cover- 

 ing consists of a mass of very fine threads, the mycelium. 

 Here and there one of the threads pierces the skin of the 

 leaf. What for ? It gets food from the juices on the inside 



